Dowel lapping machine



Aug. 27, 1935. A T. WALKER 2,012,555

DOWEL LAPPING MACHINE Filed Nov. 27, 1953 `HMI INVENTOR.

. BY F y Mmm ATTORN YS.

' :4-UNITED Patented Aug. 27, 1935v DOWELLAPPING ,l

A Arthurr'ltvlalker, Berkeley,f0alif`. y AppliatiNmy/embe 2 7, icsaiserialnolseasr f Tsolaiin's., (cisl-59)Y t ofvmovementfof the-plates.' The plates' arelrerciprocatedin'opposition to" each other andv their adjacent lapping vsurfaces engage thelengths of dowelingv supported therebetween'and create a lapping.v action, lappingthe lengths of doweling so that the Asame will be perfectly straight, uni# form in diameter from end`to en'd, smooth in flnish,and-truly roundin cross-sectional forth. ifine formwhich tl'ie invention may assum is exemplified inthe following description jandillustratedbyway-ofeirample in the accompanying drawing, in which I Y Fig. 1 is a view in side elevation of a machine embodyingthe preferred form of my invention,

with parts thereof broken away. and in vsection to illustrate certain details of construction;

` Fig. 2 is a'plan view of the machine witha portion of the upper lapping plate broken away to disclose the work-holdingy devices for support-y ing the doweling between the lapping plates;

Fig. 3 is a View in transverse section taken on line III-III of Fig. 2, looking in the direction of the arrows; and

Figs. 4 and 5 are perspective views of the workholding members in the relative positions which they assume on the `frame between the lapping plates.

Referring more particularly to the accompanying drawing, Il) indicates a machine for lapping lengths of doweling. It is contemplatedthatthe machine be used in the manufacture-of arrows and itis well known that 'straightnesa uniformity of diameter, trueness of formyand smoothness of finish are essential requisites of good arrows.

'I'he machine illustrated. includes a rigid stationary frame II, of any suitable construction and which is here illustrated as composed of a horizontal` section I2 supported by rigid uprights I4. Atone end of the frame, the horizontal section I2 is tted with bearings I5 rotatably supporting a crank shaft I6 which is arranged transversely ofthe frame, as illustrated. A pulley I1 is rarrangedat 'one s iae oftherrameiaad-is secured von aprojecting end of the vcranlfrfslfiaft I6. Rotationfis impartedto the-"crank shaft through tljiexrne'dium1 of" this pulley] 1, butf it4 is" obvious jthatia driving medium for the"`crank`v f' shaft may' bel mounted direc'tly-on'thefframe l or closely* adjacenttheret and directly .connected to the crank shaft for operating the` same.

. Thelerankfsnaft |s is formed with twg throws" or cranks I 8- and Iilfwhichy are disposed at 4180" apart.f"At theend'of theframe II opposite'the crank 1 shaiftf are two longitudi'nally` y arrangedguide` members y2II, vwhich "are disposed Yonefat each side of the horizontal section' vI2 of theframe and rigidly secured thereto. `Transv'ersely arranged roller shafts -ZI aref 'supported at theirA Y ends 'in theV guidemembe'rs 20, y'and l'each shaftf is fitted with a'pair of idler rollers 22; The rollers inners'ides of the -guide members, fasillustrated.

iguidefdf' thereby"forreciprocation longitudinally of the frame II, abovethe horizcntal'section- I2 thereof, is a lower lapping plate 23. lapping plate 23 is supportedby the rollers 22 and is freely movable thereoverfduring operation. The lapping plate is, of course, horizontally disposed, as

' illustrated. For the-purpose of reciprocating the lower lapping plate 23, it is connected byy means of a connecting rod24`to the throw or` crank I8 of the crank shaft I6. 1

Overlying the lower lapping plate 23 is a floating upper lapping plate 25, which is also horifv zontally disposed between the' guide membersl 20" and guided by the latter for reciprocation lon-` gitudinally of the frame II. The upper lapping plate 25 is connected to the throw or crank I9 of the crank shaft I6 by means of a connecting rod 26.

Inasmuch as vthe throws I8 and I9 of the crank shaft I6' are arrangedat 180 apart, the upper Vand lower lappingplates will reciprocate in opposition to each other. The under surface of the upper lapping plate 25 and the upper surface of the lower lapping plate 23 are abrasive in ,character, and in the present instance I have illustrated these lapping surfacesof the plates 23 and 25 as formed of sandpaper, or a like substance, extending over the entire lapping area thereof. The lower lapping plate 23 is formed with a number of spaced vertical openings 21 so that dust or cuttings will not accumulate on the lapping surface thereof.

Extending laterally between the guides 20 and interposed between the lapping surfaces of the bers 28.

2 i v f n plates 23 and 25 is a pair of work-.holding memthrough openings in the guides 20 and are connected to clips 29 securedat the exterior of the guides. The connection between the work-hold# ing members 28 and the clips 29 is such that the lposition of the members 28 may be adjusted so that they will accommodate doweling of different lengths for lapping. It will be noticed that the opposite .facesiof the work-holding Y,members 28 are so formedas to engage the ends of afplue rality of lengths of doweling to hold the sarnfe at a slight angle tothe path of travel on reciproca-.5l

tion of the lapping plates 23 and 25; 'I'he work-Wk holding members 28 `are less in thickness than the"l diameter of the doweling andaremso `Apositioned A that the lengths of doweling supported thereby will be engagedat opposite sides by'ithellapping surfaces of the plates 23 and 25. l

In `operation of the device, itis constiwictedv andessembled asgillustrated and describedI The lengths' of-doweling to be lapped are then; inter-I posed between the Ylapping surfacesof--thejplates Y 23 and 2.5 and engaged at theirv ends by the-work-y @5 willl createiadapping action on -the lengths ofl doweling fir'iterposed` between the .lappingsurfaces thereof. lDue to theangular arrangement of the lengths of doweling, the samewill'revolve vso that 1 .alljsurfaces thereoffwill beexposed tothe lap ping action.y `'If'his action-issuch that the lengths of doweling, when thelapping operation ;is'jcom ,pleted, willbe;perfectlystraght, unif-orm` in diameter,'smoothiinflnishv and; perfectly round'in cross-Isectional form.-

The' ends of these members project yFrom the foregoing it is `obvious that I have `provided a comparatively simple machine which will be inexpensive to construct and operate and which will operate efciently inv lapping simultaneously a considerable-number of lengths of doweling so that the same Will be perfectly Y straight, uniform in diameter from end to end,

.and perfectly round in cross-sectional form.

While I have shown the preferred form of my invention, it is to be understood that various changes may be made in `the machine Without departing' from the invention 'a's defined in the appended claims. A

Having described my invention, what I claim andjdesire tosecure by Letters Patent is- 1N.-A, machi ne for lapping dowels comprising 'spaced lapping plates mounted for oscillation and workholding means consisting of stationary bars disposed rbetween the lapping'plates to prevent axial movement of kdowels placed between the plates, said bars beingshapedgtohold the dowels at anangle tothe direction of. oscillation of the plates.. n.

y 2, a `dowei lapping f'r'lachine; the 'cmnbiri-A tion; with-spaced oscillating lapping plates of ,work-holding means `comprising stationary f bars disposed between the plates,;sad barsvbeing' ar- Y rangedto engage the ends of -a plurality of rdowels loosely to permit themy to be rotated by. the lapping 4 action ofthe' plates and to Aretain them' at an angle to the direction'of oscillation of. the platesx. ,y v n m x 3.;,In adowel,lapping machinetrthe combination'rwith spacedoscillating lapping plates-of workfholding means comprising v,stationary bars disposed between the plates Lat right anglesfto the directionkof oscillation rof the plates, one: of said vbars having a centralrecess to receive` the ends-of a group ofldowels and the other bar hav- Ain ga pair of recessesvspaced from its centerto receive .thelopposite ends of said dowels 13o-main,-

tain'the dowels in a proper position to bellapped.

j T. WALKER; ze 

